I'm working on Gitlab SE & Jenkins integration.

When I push a commit to my git repository, a new push notification is sent from Gitlab to Jenkins.
In jenkins the job execution is scheduled twice.

The first one is correct and seems to be the result of Gitlab push notificación as it states "Started ​by ​GitLab ​push ​by... "

The second one fails but it is probably started by git-plugin as it states:
"Started by an SCM change..."
It fails because the variable "gitlabSourceBranch" is not set. This shows me that this build wasn't started by the gitlab plugin.

"Poll SCM" trigger is disabled in my job configuration.

In Jenkins log I see there is only one push notification from Gitlab which is correct.

I am expecting one push -> one build.